Check Engine Light

[Jerky_san]

I had my check engine light come on today and took it in.. Was told my A/F ratio was below spec.. Was wanting to know if you all thought below spec was to rich or to lean? Also I'd have to say that this was the best experience I've had with a dealer since owning cars.. The service rep was incredibly friendly and helpful at that. Truthfully I was surprised at how friendly he was.. I had been getting bad mpg up until I filled my radiator fluid up but I'm wondering if I'll get even better if it was running to rich. Anyways do you all think to rich or to lean?

[NCJack]

Im wondering, why did you need to fill the radiator? Was it low or was it a change? I ask because im on the train of thought that maybe you could be running lean since running lean causes a hotter combustion which in turn could cause her to boil off some coolant...maybe?

Just an off the wall thought.

Regards,
Jack

[Jerky_san]

Truthfully when I bought it it was close to low. I just never filled it. This winter I was looking at different things that could cause me to get horrible mpg since I was getting an average of like 22-24 mpg. Even with highway driving and such. So I filled it to the max line and suddenly my MPG went from the lows to 28-33. My all highway driving a near 360 miles netted me 33 MPG. So I was really happy but the thing I'm worried about is if it really was running lean then I suppose my gas mileage will go to crap again. Then I'll regret ever taking it in. I will say though that for people getting bad mileage I'd suggest checking that cause it was a drastic change for me in MPG.

[Promise Land]

If you take "below" meaning the A/F ratio was numerically below the target of ~14:1 (stoichometric ratio is ~14.3:1 IIRC), it would be rich. A example ratio of 18:1 would mean more air and less fuel (running lean). Less air, more fuel, makes the ratio numerically less.